Shoe Upper Structure and Shoe Having the Same

ABSTRACT

A shoe upper structure includes an inner upper having a foot-dorsum top portion that covers at least a dorsum top region of a foot of a shoe wearer, an outer upper having a heel portion that covers at least a heel region of the foot of the shoe wearer, and a stretchable portion that generates a tensional force to the foot-dorsum top portion of the inner upper toward a lower end of the heel portion of the outer upper when the shoe is worn by the shoe wearer.

BACKGROUND OF THE INVENTION

The present invention relates generally to an upper structure for a shoe and a shoe with the upper structure that can improve holdability or holding properties relative to a heel region of a foot of a shoe wearer.

U.S. Pat. No. 4,438,574 discloses a sports shoe (10) with an upper structure that comprises a stretchable inner layer (40) and a non-stretchable outer layer (42) in a forepart section of the shoe (see column 4, lines 32-39 and FIGS. 1-4). The forepart section refers to a toe part of the shoe (see column 3, lines 60-63).

According to U.S. Pat. No. 4,438,574, the stretchable inner layer (40) stretches a limited amount to conform to the shape of a forepart section of the foot (see column 3, lines 11-13) to achieve a proper fit, and the non-stretchable outer layer (42) prevents the stretchable inner layer (40) from stretching out of shape and losing a proper fit about the forepart section of the foot (see column 3, lines 17-21).

However, the above-mentioned upper structure focuses on a fitting property of only the forepart section of the foot because the inner layer (40) is provided to tighten the entire forepart section of the foot equally and the outer layer (42) is provided to completely overlap the inner layer (40). On the other hand, according to U.S. Pat. No. 4,438,574, a general heel reinforcing member is merely provided at a heel part of the upper structure. In the above-mentioned upper structure, it is possible to some degree to exhibit a holdability of the heel reinforcing member relative to a heel part of the foot by tightening a shoelace to press an instep part of the foot to a sole side of the shoe. However, in a sports shoe, especially in an indoor sports shoe accompanied by an intense lateral movement, a more holdability is required.

Incidentally, a tongue band is known in the art in which a part of a tongue is fixedly attached to a bottom portion of an upper of a shoe, and a gusset tongue is also known in the art in which a tongue is connected to an upper body of a shoe. Since those tongues are both provided to tighten a foot vertically, they are not enough to improve holdability of a heel region of the foot.

The present invention has been made in view of these circumstances and its object is to provide a shoe upper structure that can improve holdability relative to a heel region of a foot of a shoe wearer. The present invention is also directed to providing a shoe with such a shoe upper structure.

Other objects and advantages of the present invention will be obvious and appear hereinafter.

SUMMARY OF THE INVENTION

A shoe upper structure according to the present invention comprises a first upper having a foot-dorsum top portion that is configured and adapted to cover at least a dorsum top region of a foot of a shoe wearer, a second upper having a heel portion that is configured and adapted to cover at least a heel region of the foot of the shoe wearer, and a stretchable portion that generates a tensional force at the foot-dorsum top portion of the first upper toward a lower end of the heel portion of the second upper when a shoe is worn by the shoe wearer.

According to the present invention, when the shoe is worn by the shoe wearer, since the tensional force is generated by the stretchable portion at the foot-dorsum top portion of the first upper toward the lower end of the heel region of the second upper, the foot-dorsum top portion of the first upper presses onto the dorsum top region of the foot, such that thereby the heel region of the foot moves toward the heel portion of the second upper through the foot-dorsum top portion of the first upper. As a result, the heel region of the foot can be accommodated in the heel region of the second upper and held by the second upper thus improving holdability to the heel region of the foot.

The stretchable portion may include a stretchable area that is disposed at least at a part of an area extending from a position of a Lisfranc's joint of the foot to a position of a calcaneus of the foot at least either on a medial side or on a lateral side of the foot. Thereby, when the shoe is worn by the shoe wearer, the stretchable portion can generate a tensional force at a cuneiform bone side of the foot or the foot-dorsum top portion toward the calcaneus side of the foot at least either on the medial side or on the lateral side of the foot.

The stretchable portion may include a stretchable area that is disposed intersecting a transverse tarsal joint or a Chopart joint of the foot on the medial side and the lateral side of the foot. Thereby, when the shoe is worn by the shoe wearer, the stretchable portion can generate a tensional force at a cuneiform bone side of the foot or the foot-dorsum top portion toward a calcaneus side of the foot on both the medial side and the lateral side of the foot.

The stretchable portion may be disposed below the foot-dorsum top portion of the first upper. Also, one end of the stretchable portion may be connected to the foot-dorsum top portion of the first upper and the other end of the stretchable portion may extend to the lower end of the heel portion of the second upper. Thereby, when the shoe is worn by the shoe wearer, the stretchable portion can generate a tensional force at the foot-dorsum top portion of the first upper toward the lower end of the heel portion of the second upper.

The first upper may be disposed inside or outside the second upper.

The first upper may constitute a tongue portion of the shoe. That eliminates the need to provide a tongue portion separately from the first upper thus simplifying the structure to reduce a manufacturing cost and allowing the shoe to be lighter in weight.

The first upper may include the stretchable portion that is integrated with the first upper and that constitutes a part of the first upper, such that thereby a stretchability or an elasticity of the first upper is greater than a stretchability or an elasticity of the second upper. Also, the first upper and the second upper are overlapped with one another and an overlapped area between the first upper and the second upper is separated from one another.

In this case, it becomes possible that only the first and second upper constitute the entire upper structure thus simplifying the structure to reduce a manufacturing cost and allowing the shoe to be lighter in weight. Moreover, in this case, since the first and second uppers overlap one another, as the first upper with the stretchable portion expands, the second upper can exhibit a shape retainability for retaining an upper shape thus further improving a holdability of the foot. Furthermore, in this case, since the overlapped area between the first and second uppers is separated from one another, a perimeter of an access opening of the upper structure for entry of the foot is variable thus absorbing an individual difference of an instep height or an ankle perimeter, such that thereby the upper structure can correspond to various feet having an equal foot length/foot width but a different instep height/ankle perimeter.

The second upper may include an access opening for entry of the foot into the shoe and a throat opening that extends longitudinally in connection with the access opening. Also, the first upper may include a tongue portion disposed at the throat opening, the stretchable portion may be disposed below the first upper, and an end of the stretchable portion may be connected to the first upper and the other end of the stretchable portion may extend to the lower end of the heel portion of the second upper.

That eliminates the need to provide a tongue portion separately from the first upper thus simplifying the structure to reduce a manufacturing cost and allowing for the shoe to be lighter in weight. Also, when the shoe is worn by the shoe wearer, the stretchable portion can apply a tensional force to the foot-dorsum top portion of the first upper toward the lower end of the heel portion of the second upper.

A shoe of the present invention may comprise the shoe upper structure of the current invention and a sole, and a bottom portion of the upper structure may be fixedly attached to the sole.

As above-mentioned, according to the present invention, when the shoe is worn by the shoe wearer, since the stretchable portion generates a tensional force at the foot-dorsum top portion of the first upper toward the lower end of the heel portion of the second upper, the foot-dorsum top portion of the first upper presses onto the dorsum top region of the foot, such that thereby the heel region of the foot moves toward the heel portion of the second upper through the dorsum top portion of the first upper. As a result, the heel region of the foot can be held by the second upper thus improving holdability of the heel region of the foot.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the invention, reference should be made to the embodiments illustrated in greater detail in the accompanying drawings and described below by way of examples of the invention.

FIG. 1 is a medial side view of a sports shoe (for a right foot) having a shoe upper structure according to an embodiment of the present invention.

FIG. 2 is a lateral side view of the sports shoe of FIG. 1.

FIG. 3 is a top plan view of the sports shoe of FIG. 1.

FIG. 4 is a medial side view of the sports shoe and illustrates an inner upper (or first upper) and an outer upper (or second upper) constituting the shoe upper structure of FIG. 1, showing the state that a shoelace is removed from the shoe of FIG. 1.

FIG. 5 is a lateral side view of the sports shoe and illustrates the inner upper (or first upper) and the outer upper (or second upper) constituting the shoe upper structure of FIG. 2, showing the state that the shoelace is removed from the shoe of FIG. 2.

FIG. 6 is a top plan view of the sports shoe and illustrates the inner upper (or first upper) and the outer upper (or second upper) constituting the upper structure of FIG. 3, showing the state that the shoelace is removed from the shoe of FIG. 3.

FIG. 6A is a cross sectional view of FIG. 6 taken along line VIA-VIA.

FIG. 7 illustrates the shoe upper structure of FIG. 4 schematically.

FIG. 8 illustrates the shoe upper structure of FIG. 5 schematically.

FIG. 9 illustrates the shoe upper structure of FIG. 7 along with a bone structure of the foot of a shoe wearer.

FIG. 10 illustrates the shoe upper structure of FIG. 8 along with the bone structure of the foot of the shoe wearer.

FIG. 11 illustrates the shoe upper structure of a first alternative embodiment of the present invention schematically.

FIG. 12 illustrates the shoe upper structure of a second alternative embodiment of the present invention schematically.

FIG. 13 illustrates the shoe upper structure of a third alternative embodiment of the present invention schematically.

FIG. 14 illustrates the shoe upper structure of a fourth alternative embodiment of the present invention schematically.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will now be described in detail with reference to embodiments thereof as illustrated in the accompanying drawings.

Referring to the drawings, FIGS. 1 to 10 show a shoe upper structure according to an embodiment of the present invention and a sports shoe employing the shoe upper structure. FIGS. 1 to 6 are external views of the shoe (for a right foot), FIG. 6A is a cross sectional view of the shoe, and FIGS. 7 to 10 schematically show the shoe upper structure. Here, an indoor shoe for ball games such as a volleyball, handball and the like is taken for an example as a sports shoe.

In the following explanations, “upward (upper side/upper)” and “downward (lower side/lower)” designate an upward direction and a downward direction, respectively, or vertical direction of the shoe, “forward (front side/front)” and “rearward (rear side/rear)” designate a forward direction and a rearward direction, respectively, or longitudinal direction of the shoe, and “a width or lateral direction” designates a crosswise direction of the sole. For example, when FIG. 1, or the medial side view of the shoe, is taken as an example, “upward” and “downward” generally designate “upward” and “downward” in FIG. 1, respectively, “forward” and “rearward” generally designate “left to right direction” in FIG. 1, respectively, and “a width direction” generally designates “out of the page” and “into the page” of FIG. 1, respectively.

As shown in FIGS. 1 to 3, a sports shoe 1 includes an upper 2 that is disposed along an entire length of the shoe 1 to cover an entire foot of a shoe wearer, and a midsole 3 that is fixedly attached to a bottom portion of the upper 2.

The upper 2 comprises an inner upper (or a first upper) 20 disposed on an inner side of the shoe 1 and an outer upper (or a second upper) 21 disposed on an outer side of the shoe 1, that is, outside the inner upper 20. In this exemplification, the inner upper 20 is formed with a tongue of the shoe 1. At a top portion of the outer upper 21, there are formed an access opening 10 for a foot entry and a throat opening 10 a that extends longitudinally in connection with the access opening 10. On opposite side end edge portions of the throat opening 10 a, there are formed a plurality of eyelets 2 a into which a shoelace 11 as a tightening member of the shoe 1 is inserted.

A heel counter 4 is provided at a heel portion of the shoe 1 and inside the outer upper 21. The heel counter 4 is a thin hard member and has a U-shape as viewed from above that extends from a heel medial side through a heel rear end to a heel lateral side. The heel counter 4 is adapted to maintain a shape retainability of the heel portion of the outer upper 21 and to contribute to a holdability of the heel region of the foot. On a bottom surface of the midsole 3, an outsole 5 with a ground contact surface to contact the ground/floor is fixedly attached. The midsole 3 and the outsole 5 constitute a sole of the shoe 1.

As shown in FIGS. 4 to 6, the inner upper 20 overlaps with the throat opening 10 a of the outer upper 21 and has a portion functioning as a tongue of the shoe 1. The inner upper 20 extends beyond the throat opening 10 a longitudinally to a tip of a toe and laterally to lower ends of a medial side and a lateral side (see dotted lines of the drawings). The inner upper 20 comprises a body portion (a first upper portion) 20A disposed to cover a generally entire region of a dorsum (or an instep) region of the foot of the shoe wearer and a stretchable portion 20B disposed below the body portion 20A and having a stretchability or elasticity/expansibility. An upper end 20 b of the stretchable portion 20B is connected integrally with a lower end 20 a of the inner upper 20 by sewing or the like.

A rearward side end 20C of the inner upper 20 extends diagonally downwardly toward a lower end of the heel portion. In this exemplification, the stretchable portion 20B is a generally triangular area with an apex disposed on the rearward side end 20C of the inner upper 20. The upper end 20 b of the stretchable portion 20B and the lower end 20 a of the inner upper 20 extend diagonally downwardly in a forward direction. Respective lower ends of the body portion 20A and the stretchable portion 20B are fixedly attached to the midsole 3. A rearmost end 20Bb of the stretchable portion 20B is disposed at a lower end of the heel portion of the outer upper 21.

According to such a structure, when the shoe 1 is worn by the shoe wearer, the stretchable portion 20B of the inner upper 20 stretches to expand elastically, such that thereby a tensional force (or tension) P is generated by the stretchable portion 20B at the body portion 20 A toward the lower end of the heel portion of the outer upper 21. By the action of the tensional force P, the dorsum top region of the foot of the wearer is pressed diagonally downwardly in a rearward direction, and the heel region of the foot is thus accommodated and held in the heel portion of the outer upper 21. The upper structure of the present embodiment is structured by the outer upper 21 and the inner upper 20 formed of the body portion 20A and the stretchable portion 20B.

In FIG. 6, a shaded area enclosed by a dash-and-dot line designates a foot-dorsum top portion 20A₀ of the inner upper 20, which corresponds to the dorsum top region of the foot. The inner upper 20 includes at least the foot-dorsum top portion 20A₀. Also, the outer upper 21 includes at least the heel portion.

FIG. 6A is a cross sectional view of FIG. 6 taken along line VIA-VIA and shows a cross section at which the stretchable portion 20B of the inner upper 20 is not provided. The lower end of the body portion 20A of the inner upper 20 is fixed to the midsole 3 and an insole board 30 disposed on the midsole 3 via bonding, sewing or the like along with the lower end of the outer upper 21. Also, the outer upper 21 is provided to overlap with the body portion 20A of the inner upper 20, but separated from the body portion 20A of the inner upper 20 except the respective lower ends of the outer upper 21 and the body portion 20A.

The same holds true for a cross section where the stretchable portion 20B of the inner upper 20 is provided. It is not shown, but the lower end of the stretchable portion 20B of the inner upper 20 is fixed to the midsole 3 and the insole board 30 disposed on the midsole 3 via bonding, sewing or the like along with the lower end of the outer upper 21. Also, the outer upper 21 is provided to overlap with the stretchable portion 20B of the inner upper 20, but separated from the stretchable portion 20B of the inner upper 20 except the respective lower ends of the outer upper 21 and the stretchable portion 20B.

In addition, an inner circumferential length or an inner perimeter measured along an inner circumferential surface of the inner upper 20 at a cross section where the stretchable portion 20B is provided is shorter than an outer circumferential length or an outer perimeter measured along an outer circumferential surface of a last for manufacturing the shoe upper structure at the above-mentioned same cross section where the stretchable portion 20B is provided. Therefore, when the shoe 1 is worn by the shoe wearer, the stretchable portion 20B of the inner upper 20 stretches to expand elastically, such that thereby the tensional force (or tension) P generated by the stretchable portion 20B acts onto the dorsum top region of the foot.

The body portion 20A of the inner upper 20 may be formed of artificial leather, synthetic leather, mesh material of a low elasticity, and the like. The stretchable portion 20B may be formed of elastic fibers such as for example, spandex (or polyurethane elastic yarn). The outer upper 21 may be formed of artificial leather, synthetic leather, mesh material of a low elasticity, and the like.

The midsole 3 maya be formed of a soft elastic material, more specifically, thermoplastic synthetic resin and its foamed resin such as ethylene-vinyl acetate copolymer (EVA) or the like, thermosetting synthetic resin and its foamed resin such as polyurethane (PU) or the like, alternatively, rubber material and foamed rubber such as butadiene rubber, chloroprene rubber or the like. The outsole 5 may be formed of a hard elastic material, more specifically, thermoplastic resin such as thermoplastic polyurethane (TPU), polyamide elastomer (PAE) and the like, thermosetting resin such as epoxy resin and the like, or solid rubber.

Then, FIGS. 7 and 8 schematically illustrate the upper structure of FIGS. 4 and 5, respectively. In these drawings, the midsole 3 and the outsole 5 are not shown and only the upper 2 is shown. In FIGS. 7 and 8, a solid line designates the inner upper 20, a dash-and-dot line designates the outer upper 21, and a gray area designates the stretchable portion 20B.

FIGS. 9 and 10 respectively show the upper structure of FIGS. 7 and 8 along with a bone structure of the foot. In these drawings, reference characters H, M and F indicate a heel portion, a midfoot portion, and a forefoot portion of the upper 2, respectively. Also, reference character MT indicates and stands for metatarsus of the foot, CmB for cuneiform bone, NB for navicular bone, CdB for cuboid bone, TA for talus, and CA for calcaneus, respectively, and LF for Lisfranc's joint and TT for Chopart joint or transverse tarsal joint, respectively.

As shown in FIG. 9, on the medial side of the foot, the extendable portion 20B is disposed at least at a portion of an area extending from the cuneiform bone Cmb through the navicular bone NB and the talus TA to the calcaneus CA. Also, the upper end 20 b of the stretchable portion 20B crosses the cuneiform bone Cmb, the navicular bone NB and the talus TA, and intersects at least the Chopart joint TT, alternatively both the Chopart joint TT and the Lisfranc's joint LF. The rearmost end 20Bb of the stretchable 20B is disposed at a bottom portion of the calcaneus CA.

As shown in FIG. 10, on the lateral side of the foot, the extendable portion 20B is disposed at least at a portion of an area extending from the cuboid bone CdB to the calcaneus CA. Also, the upper end 20 b of the stretchable portion 20B crosses the cuboid bone CdB and intersects at least the Chopart joint TT, alternatively both the Chopart joint TT and the Lisfranc's joint LF. The rearmost end 20Bb of the stretchable 20B is disposed at the bottom portion of the calcaneus CA.

According to the present invention, when the shoe 1 is worn by the shoe wearer, as the stretchable portion 20B stretches to expand to generate and apply a tensional force (or tension) P to the foot-dorsum top portion 20A₀ of the inner upper 20 toward the lower end of the heel portion H of the outer upper 21 (see FIGS. 7 to 10), the foot-dorsum top portion 20A₀ of the inner upper 20 presses against the dorsum top region of the foot. Thereby, the heel region of the foot moves toward the heel portion H of the outer upper 21 through the foot-dorsum top portion 20A₀. As a result, the heel region of the foot can be held by the outer upper 21 thus improving holdability of the heel region of the foot.

In the present embodiment, since the upper end 20 b of the stretchable portion 20B is disposed at least at a portion of an area extending from the cuneiform bone CmB to the calcaneus CA on the medial side of the foot, when the shoe 1 is worn by the wearer, the stretchable portion 20B can impart the tensional force (or tension) P to the side of the calcaneus CA on the medial side of the foot from the side of the cuneiform bone CmB, i.e. the side of the foot-dorsum top portion 20A₀.

In the present embodiment, since the upper end 20 b of the stretchable portion 20B is disposed intersecting the Chopart joint TT on the medial and lateral sides of the foot, when the shoe 1 is worn by the wearer, the stretchable portion 20B can impart the tensional force (or tension) P to the side of the calcaneus CA on the medial and lateral sides of the foot from the side of the cuneiform bone CmB, i.e. the side of the foot-dorsum top portion 20A₀.

In the embodiment, since the stretchable portion 20B has a generally triangular shape with an apex disposed on the rearward side end 20C of the inner upper 20, the stretchable portion 20B is easiest to stretch on the rearward side end 20C, such that thereby the rearward side end 20C of the stretchable portion 20B can follow the contour of the three-dimensional shape of the heel region of the foot.

In the present embodiment, since the inner upper 20 comprises the body portion 20A to cover the dorsum top region of the foot and the stretchable portion 20B disposed below and coupled with the body portion 20A, when the shoe 1 is worn by the wearer, the body portion 20A of less elasticity can hold the dorsum top region of the foot firmly and the stretchable portion 20B can exert the tensional force (or tension) P to the body portion 20A toward the side of the calcaneus CA of the outer upper 21.

In this embodiment, since the inner upper 20 is disposed inside the outer upper 21, when the shoe 1 is worn by the wearer, the outer upper 21 can hold the stretchable portion 20B of the inner upper 20 from the outside to improve holdability of the heel region of the foot while allowing a stretch of the stretchable portion 20B of the inner upper 20.

In the present embodiment, the inner upper 20 constitutes the tongue of the shoe 1, which eliminates the need to provide a tongue portion separately from the inner upper 20 thus simplifying the structure to reduce a manufacturing cost and allowing for the shoe to be lighter in weight.

In the present embodiment, the inner upper 20 has the stretchable portion 20B integrated therewith and constituting a part of the inner upper 20. Also, the inner upper 20 and the outer upper 21 are overlapped with one another and an overlapped area between the inner upper 20 and the outer upper 21 is separated from one another.

Thereby, it becomes possible to constitute the entire shoe upper structure with only the inner upper 20 and the outer upper 21 thus simplifying the structure, reducing the cost, and saving the weight of the shoe 1. Also, since the inner upper 20 and the outer upper 21 overlap with one another, the outer upper 21 can exhibit a shape-retaining property to hold an upper shape thus improving a holdability of the foot when the inner upper 20 with the stretchable portion 20B stretches. Moreover, since an overlapped area between the inner upper 20 and the outer upper 21 is separated from one another, the perimeter (or the length of the circumference) of the entry opening 10 of the upper structure is variable, such that thereby an individual difference of an instep height or an ankle perimeter can be absorbed to correspond to various feet having an equal foot length/foot width but a different instep height/ankle perimeter. In addition, a stretchability of the entire inner upper 20 is greater that a stretchability of the outer upper 21.

Alternative embodiments of the present invention will be hereinafter explained. In drawings showing the alternative embodiments, like reference characters indicate identical or functionally similar elements.

First Alternative Embodiment

In the above-mentioned embodiment shown in FIGS. 1 to 10, an example was shown in which both the inner upper 20 and the outer upper 21 extend to the distal end of the forefoot portion F, i.e. the tip of the toe of the foot, but the application of the present invention is not restricted to such an example. In this first alternative embodiment, as shown in FIG. 11, although the outer upper 21 extends to the distal end of the forefoot portion F, the inner upper 20 does not extend to the distal end of the forefoot portion F and its fore end 20 f remains at a longitudinally intermediate position of the forefoot portion F. The stretchable portion 20B of the inner upper 20 forms a triangular shape as with the above-mentioned embodiment.

In this case as well, in wearing the shoe 1, the stretchable portion 20B applies the tensional force (or tension) P to the foot-dorsum top portion 20A₀ of the inner upper 20 toward the lower end of the heel portion H of the outer upper 21. Then, the foot-dorsum top portion 20A₀ of the inner upper 20 presses against the dorsum top region of the foot, such that thereby the heel region of the foot moves toward the heel portion H of the outer upper 21 through the foot-dorsum top portion 20A₀. As a result, the heel region of the foot can be held by the outer upper 21 thus improving holdability of the heel region of the foot.

Second Alternative Embodiment

In the above-mentioned embodiment shown in FIGS. 1 to 10, an example was shown in which both the inner upper 20 and the outer upper 21 extend to the distal end of the forefoot portion F, but the application of the present invention is not restricted to such an example. In this second alternative embodiment, as shown in FIG. 12, although the inner upper 20 extends to the distal end of the forefoot portion F, the outer upper 21 does not extend to the distal end of the forefoot portion F and its fore end 21 f remains at a frontend position of the midfoot portion M. The stretchable portion 20B of the inner upper 20 forms a triangular shape as with the above-mentioned embodiment.

In this case as well, in wearing the shoe 1, the stretchable portion 20B imparts the tensional force (or tension) P to the foot-dorsum top portion 20A₀ of the inner upper 20 toward the lower end of the heel portion H of the outer upper 21. Then, the foot-dorsum top portion 20A₀ of the inner upper 20 exerts a pressure onto the dorsum top region of the foot, such that thereby the heel region of the foot moves toward the heel portion H of the outer upper 21 through the foot-dorsum top portion 20A₀. As a result, the heel region of the foot can be held by the outer upper 21 thus improving holdability of the heel region of the foot.

Third Alternative Embodiment

In the above-mentioned embodiment shown in FIGS. 1 to 10, an example was shown in which both the inner upper 20 and the outer upper 21 extend to the distal end of the forefoot portion F, but the application of the present invention is not restricted to such an example. In this third alternative embodiment, as shown in FIG. 13, although the inner upper 20 extends to the distal end of the forefoot portion F, the outer upper 21 does not extend to the distal end of the forefoot portion F and its fore end 21 f remains at a front end position of the midfoot portion M. The stretchable portion 20B of the inner upper 20, unlike the above-mentioned embodiment, forms a belt-like shape extending from the dorsum-top portion to the heel lower end along the rear side end 20C of the inner upper 20.

In this case as well, in wearing the shoe 1, the stretchable portion 20B imparts the tensional force (or tension) P to the foot-dorsum top portion 20A₀ of the inner upper 20 toward the lower end of the heel portion H of the outer upper 21. Then, the foot-dorsum top portion 20A₀ of the inner upper 20 exerts a pressure onto the dorsum top region of the foot, such that thereby the heel region of the foot moves toward the heel portion H of the outer upper 21 through the foot-dorsum top portion 20A₀. As a result, the heel region of the foot can be held by the outer upper 21 thus improving holdability of the heel region of the foot.

Fourth Alternative Embodiment

In the above-mentioned embodiment shown in FIGS. 1 to 10 and the first to third alternative embodiments shown in FIGS. 11 to 13, respectively, an example was shown in which the body portion 20A of the inner upper 20 has the stretchable portion 20B integrated with the body portion 20A and constituting the inner upper 20 along with the body portion 20A, but the application of the present invention is not restricted to such an example.

FIG. 14 shows a fourth alternative embodiment of the present invention. In this alternative embodiment, the inner upper 20 is provided as the tongue 20A and the stretchable portion is provided as a stretchable belt 20B of a belt-shape. The upper end of the stretchable belt 20B is coupled to the rearward end portion (or the right side end portion in FIG. 14) of the inner upper 20 via sewing and the like and the lower end of the stretchable belt 20B is fixedly attached to the lower end of the heel portion of the outer upper 21.

In this case as well, in wearing the shoe 1, the stretchable belt 20B imparts the tensional force (or tension) P to the inner upper 20 toward the lower end of the heel portion H of the outer upper 21. Then, the dorsum top region of the foot is pressed diagonally downwardly, such that thereby the heel region of the foot moves toward and is accommodated by the heel portion H of the outer upper 21 and it can thus be held by the outer upper 21.

Fifth Alternative Embodiment

In the above-mentioned embodiment shown in FIGS. 1 to 10 and the first and second alternative embodiments shown in FIGS. 11 and 12, respectively, an example was shown in which the stretchable portion 20B has a triangular shape as viewed from the side, but the application of the present invention is not restricted to such an example. The stretchable portion 20B may be a rectangular shape as viewed in the longitudinal direction, a polygonal shape, an oval/elliptical shape, or the like.

Sixth Alternative Embodiment

In the above-mentioned embodiment shown in FIGS. 1 to 10 and the first to fifth embodiments shown in FIGS. 11 to 14, respectively, an example was shown in which the inner upper (i.e. the first upper) 20 with the foot-dorsum top portion 20A₀ is disposed inside the outer upper (i.e. the second upper) with the heel portion 21, but an inside and outside positional-relation between the inner upper 20 and the outer upper 21 may be opposite. That is, the first upper 20 may be disposed outside the second upper 21.

Seventh Alternative Embodiment

In the above-mentioned embodiment shown in FIGS. 1 to 10 and first to fifth embodiments shown in FIGS. 11 to 14, respectively, an example was shown in which the inner upper 20 and the outer upper 21 are overlapped with one another, but the application of the present invention is not restricted to such an example. The inner upper 20 and the outer upper 21 may not be necessarily overlapped with one another. In that case, in a boundary portion between the inner upper 20 and the outer upper 21, a third upper or an interior material may be disposed.

Other Application

In the above-mentioned embodiment and the first to seventh alternative embodiments, an example was shown in which the present invention was applied to indoor shoes for ball games such as a volleyball, handball and the like, but the present invention also has application to indoor shoes for racquet games such as a tennis, badminton, table tennis and the like. The present invention is further applicable to other sports shoes and shoes for daily use.

As mentioned above, the present invention is useful for shoes, especially sports shoes, and above all, an upper structure for indoor shoes to improve holdability of the heel region of the foot of the shoe wearer.

Those skilled in the art to which the invention pertains may make modifications and other embodiments employing the principles of this invention without departing from its spirit or essential characteristics particularly upon considering the foregoing teachings. The described embodiments and examples are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. Consequently, while the invention has been described with reference to particular embodiments and examples, modifications of structure, sequence, materials and the like would be apparent to those skilled in the art, yet fall within the scope of the invention. 

What is claimed is:
 1. A shoe upper structure comprising: a first upper having a foot-dorsum top portion that is configured and adapted to cover at least a dorsum top region of a foot of a shoe wearer; a second upper having a heel portion that is configured and adapted to cover at least a heel region of the foot of the shoe wearer; and a stretchable portion that generates a tensional force at said foot-dorsum top portion of said first upper toward a lower end of said heel portion of said second upper when a shoe is worn by the shoe wearer.
 2. The shoe upper structure according to claim 1, wherein said stretchable portion includes a stretchable area that is disposed at least at a part of an area extending from a position of a Lisfranc's joint of the foot to a position of a calcaneus of the foot at least either on a medial side or on a lateral side of the foot.
 3. The shoe upper structure according to claim 1, wherein said stretchable portion includes a stretchable area that is disposed intersecting a Chopart joint of the foot on a medial side and a lateral side of the foot.
 4. The shoe upper structure according to claim 1, wherein said stretchable portion is disposed below said foot-dorsum top portion of said first upper, and an end of said stretchable portion is connected to said foot-dorsum top portion of said first upper and the other end of said stretchable portion extends to said lower end of said heel portion of said second upper.
 5. The shoe upper structure according to claim 1, wherein said first upper is disposed inside said second upper.
 6. The shoe upper structure according to claim 1, wherein said first upper is disposed outside said second upper.
 7. The shoe upper structure according to claim 1, wherein said first upper constitutes a tongue portion of said shoe.
 8. The shoe upper structure according to claim 1, wherein said first upper includes said stretchable portion that is integrated with said first upper and that constitutes a part of said first upper, whereby an elasticity of said first upper is greater than an elasticity of said second upper, and wherein said first upper and said second upper are overlapped with one another and an overlapped area between said first upper and said second upper is separated from one another.
 9. The shoe upper structure according to claim 1, wherein said second upper includes an access opening for entry of the foot into the shoe and a throat opening that extends longitudinally in connection with said access opening and said first upper includes a tongue portion disposed at said throat opening, and wherein said stretchable portion is disposed below said first upper and an end of said stretchable portion is connected to said first upper and the other end of said stretchable portion extends to said lower end of said heel portion of said second upper.
 10. A shoe comprising said shoe upper structure according to claim 1 and a sole, wherein said upper structure includes a bottom portion that is fixedly attached to said sole. 